UPDATE [Friday, December 9, 2011 at 8:40am ET]: Wait time for the 2TB built-to-order iMacs has improved slightly to 2-4 weeks, per online Apple Store.

Apple sold 4.89 million Macs in its fourth fiscal 2011 quarter and the Mac business contributed with $6.27 billion in the $28.27 billion quarter. Even though more than 73 percent of Apple’s revenue came from Mac portables (mostly flash-based MacBook Airs), the remaining $1.69 billion came from hard drive-based desktop machines such as Mac Pro (some) and the popular iMac all-in-one family (the vast majority).

However, global hard drive shortage due to flooding in Thailand is now taking toll on the Cupertino, California-based gadget maker as shipping estimates for build-to-order iMac models fitted with a two terabyte hard drive slipped to 5-7 weeks. Previously, these iMacs shipped within 1-3 days so the delay is substantial…

According to AI, build-to-order iMacs with hard drive capacities under 2TB are not affected and show the usual shipping estimate of 3 to 5 days. Thailand flooding is continuing to disrupt global supply of hard drives. More than 14,000 factories are said to be affected, including Western Digital and Seagate production lines, and about 600,000 people are put out of work. According toDigiTimes, hard drive vendors are now focusing on making high-capacity and higher-profitability models, hiking prices and forcing PC makers to adopt more expensive, larger capacity hard drives.